On Sep 28, 12:02 am, Margo Schulter wrote:
Over the last seven decades, S. L. Walkden's famous article of 1936
about "The Richest-Field Telescope" (RFT) has inspired many
variations. Walkden celebrates the special charms of a small telescope
designed to show as many stars as possible in a single field of view
when sweeping the Milky Way: limiting magnitude around 11; aperture
about 3"; fast optics around f/5 or f/6; and magnification near 10X.
The exit pupil should match the full dilation of the observer's eyes.

However, I would like to consider a different kind of observing
scenario here which some might deem a self-contradiction: a
realization of Walkden's RFT ideal at a light-polluted urban site.
Can one really speak of "the RFT ideal" in skies where the Milky Way
is invisible to the naked eye?

From my own observing experience in such urban conditions, however
modest, I would answer, "Yes." Even in a heavily light-polluted area,
one can still relish having a wide-field view of the Milky Way in
Sagittarius, say, filled as richly with stars _as the circumstances
permit_.

While I can't comment on much of your post, as my own observing goals
for the present are of a different nature, I would tend to agree with
your conclusion.

After all, the dilation of the dark-adapted eye is 7mm (at least if
you're still only 30 years old) whether you are in the city or the
country, and that is what the definition of an RFT has been taken to
be.

The popular and inexpensive 7x50 binocular is another one that meets
that criterion.

John Savard